SMPL layer for PyTorch

SMPL human body [1] layer for PyTorch (tested with v0.4 and v1.x) is a differentiable PyTorch layer that deterministically maps from pose and shape parameters to human body joints and vertices. It can be integrated into any architecture as a differentiable layer to predict body meshes. The code is adapted from the manopth repository by Yana Hasson.

Installation

You can install smpl-pytorch from PyPI:

pip install smpl-pytorch

Additionally, you have to download the SMPL pickle files:

• Download the models from the SMPL website by choosing "SMPL for Python users". Note that you need to comply with the SMPL model license.
• Extract and copy the models folder into the smpl/native/ folder.

Alternatively, you can set up the package manually (see next).

Setting up

• Dependencies:
  • Install the dependencies listed in environment.yml
    • In an existing conda environment, conda env update -f environment.yml
    • In a new environment, conda env create -f environment.yml, will create a conda environment named smplpytorch
• Download SMPL pickle files:
  • Download the models from the SMPL website by choosing "SMPL for Python users". Note that you need to comply with the SMPL model license.
  • Extract and copy the models folder into the smpl/native/ folder.

Demo

Forward pass the randomly created pose and shape parameters from the SMPL layer and display the human body mesh and joints:

python demo.py

Acknowledgements

The code largely builds on the manopth repository from Yana Hasson, which implements the MANO hand model [2] layer.

The code is a PyTorch port of the original SMPL model from chumpy. It builds on the work of Loper et al. [1].

The code reuses part of the code by Zhang Xiong to compute the rotation utilities.

If you find this code useful for your research, please cite the original SMPL publication:

@article{SMPL:2015,
    author = {Loper, Matthew and Mahmood, Naureen and Romero, Javier and Pons-Moll, Gerard and Black, Michael J.},
    title = {{SMPL}: A Skinned Multi-Person Linear Model},
    journal = {ACM Trans. Graphics (Proc. SIGGRAPH Asia)},
    number = {6},
    pages = {248:1--248:16},
    volume = {34},
    year = {2015}
}

References

[1] Matthew Loper, Naureen Mahmood, Javier Romero, Gerard Pons-Moll, and Michael J. Black, "SMPL: A Skinned Multi-Person Linear Model," SIGGRAPH Asia, 2015.

[2] Javier Romero, Dimitrios Tzionas, and Michael J. Black, "Embodied Hands: Modeling and Capturing Hands and Bodies Together," SIGGRAPH Asia, 2017.